CODEWITHSUNDEEP
plc
Niclas
Niclas

Reputation: 146

PLC: If Then Else inside Function Block

I'm trying to learn by programming for a Bosch/Rexroth MLC. I wrote this sequence, but I'm not sure if there's a better way to do things.

Pseudo-code would look something like this:

wRunningCount=300
wStandstillCount=150
wCount
zeroSpeed
IF zeroSpeed THEN
    wCount=wStandstillCount
ELSE
    wCount=wRunningCount
FI

But I want to move this functionality into function blocks. (Already have a TON that will receive the wCount)

Right now I have:

                  __MOVE____
       zeroSpeed-|EN    ENO|-
wStandStillCount-|_________|-wCount


                  __MOVE___
      zeroSpeed-o|EN    ENO|-
   wRunningCount-|_________|-wCount

Is there some better way to do this?

Upvotes: 3

Views: 3963

Answers (3)

Squanchy
Squanchy

Reputation: 87

Most 61131 implementations will have a "SEL" block that should do this fairly nicely...

            __SEL__
zerospeed  |G     Q|wCount
           |       |
wrunning   |IN0    |
           |       |
wstandstill|IN1    |
           |_______|

Upvotes: 1

tkezy
tkezy

Reputation: 162

Why can't you use the ton block in ST? The rest of your code looks pretty good.

TON_0(enable:=TRUE, PT:=T#1s);

IF TON_0.Q THEN //if timer done

//do stuff

TON_0(enable:=FALSE); //reset timer

END_IF

Upvotes: 0

mrsargent
mrsargent

Reputation: 2442

depending on how you want to initialize your variables you can do this

enter image description here

Otherwise there is not better way to do it then you are right now.

Upvotes: 1

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